412 



LATERAL VENTRICLES. 



bounded above (roof) by the corpus callosum ; internally by the 

 septum lucidum, which separates it from the opposite ventricle ; and 



Fig. 139." 



* The lateral ventricles of the cerebrum. 1, 1. The two hemispheres cut 

 down to a level with the corpus callosum so as to constitute the centrum ovale 

 majus. The surface is seen to be studded with the small vascular points 

 puncta vasculosa ; and surrounded by a narrow margin which represents the 

 grey substance. 2. A small portion of the anterior extremity (genu) of the 

 corpus callosum. 3. Its posterior boundary (splenium) ; the intermediate por- 

 tion forming the roof of the lateral ventricles has been removed so as to com- 

 pletely expose those cavities. 4. A part of the septum lucidum, shewing an 

 interspace between its layers the fifth ventricle. 5. The anterior cornu of one 

 side. 6. The commencement of the middle cornu. 7. The posterior cornu. 

 8. The corpus striatum of one ventricle. Q. The tenia semicircularis covered 

 by the vena corporis striati and tenia Tarini. 10. A small part of the thalamus 

 opticus. 1 1 . The dark fringe-like body to the left of the numeral is the choroid 

 plexus. This plexus communicates with that of the opposite ventricle through 

 the foramen of Monro, or foramen commune an terms ; a bristle is passed 

 through this opening, and its extremities are seen resting on the corpus stria- 

 tum at each side. The figure 11 rests upon the edge of the fornix, upon that 

 part of it which is called the corpus fimbriatum. 12. The fornix. 13. The 

 commencement of the hippocampus major descending into the middle cornu. 

 The rounded oblong body in the posterior cornu of the lateral ventricle, directly 

 behind the figure 13, is the hippocampus minor. 



